Coping With the Obsolescence of Safety- or Mission-Critical Embedded Systems Using FPGAs

Today, many companies are facing the problem of component obsolescence in embedded systems. The incredibly fast growth rate of semiconductor companies is reducing dramatically the time components are available on the market. Twenty years ago, components remained on the market for 5 to 10 years; nowadays, they disappear from the market in less than two years. Developers of safety- or mission-critical systems are particularly sensitive to the obsolescence problem as their systems are expected to remain operative for very long periods (e.g., 30 years or more), and maintaining them fully operative is becoming difficult as the needed components may no longer be available. A possible solution for this problem may be the implementation of the needed components using FPGAs. The purpose of this paper is to provide an overview of the different possibilities designers have to face when developing such dependability-oriented solution. Also, a design flow is presented, describing its applicability to the implementation of processor cores, to be employed as a replacement of obsolete parts in safety- or mission-critical applications. Results show that there is a strong dependence of the reliability of the design with the specific application. The scrubbing process can also be optimized using the related technique.